Atrial septal defect (ASD) is one of the most common congenital heart defects, accounting for 7%-10% of all congenital Heart disease in children and 30%-33% of defects diagnosed in adults with congenital heart disease (Kazmouz et al. 2013). Secundum atrial septal defect (ASD) is a congenital heart defect in the septum between the atria of the heart, which allows blood to flow from the left atrium to the right atrium through a hole or defect in the interatrial septum. This defect is typically caused by deficiency of valve tissue of fossa ovalis, excessive or ectopic resorption of septum primum or deficient growth of septum secundum. Forty years ago, Dr. Terry D. King performed the first transcatheter closure of atrial septal defect using double umbrella disks (King et al. 1976). Since then, many devices have been developed to close such defects (King and Mills 2010). During a cardiac catheterization, a thin catheter is inserted into a blood vessel in the groin of a patient and guided to the heart. Through the catheter, a mesh patch or plug is put into place to close to close the interatrial defect. The heart tissue grows around the mesh permanently sealing the defect.
However, patients with ASD and inadequate rims are not good candidates for the available devices or may pose significant technical challenges seating the device well (Podnar et al. 2001; Amin 2006; Kannan, et al. 2003). An inadequate rim of tissue around the ASD may not allow for proper device anchoring leading to device malposition. The most common site of deficient rim is the retroaortic area (also called the anterior-superior rim) which may be deficient in up to 45% of patients with ASD (Knirsch et al., 2005; cited in Love, et al., 2012).
Therefore, currently, many of these patients are referred for traditional surgical closure of their defects (Moore et al. 2013; Gokaslan et al. 2012). However, an inadequate rim is one of the serious challenges for transcatheter closure of ASD, making this treatment modality impossible in many occasions (Li et al. 2012. The purpose of this invention is to modify these defects (defects with deficient or inadequate rims) and to make their defects more feasible for transcatheter closure.